Microbial leaching of El-Sella mineralisation by Aspergillus clavatus- a fact of fungal–uranium interface

ABSTRACT

This study evaluates the bioleaching of uranium from El-Sella mineralisation by Aspergillus clavatus. A. clavatus was generally found to give the maximum bioleaching efficiency of uranium under two-step bioleaching process when a total concentration of 3% (w/v) El-Sella mineralisation was applied. Microscopic examination revealed that bioleaching negatively affected fungal vesicles, and resulted in the formation of a swollen pellet structure in the mycelium. Uranium precipitated as uranium calcium phosphate mineral (Autunite) crystals on the surface of hyphae. Finally, the purity of uranium assayed was 73.19% in sodium diuranate. In conclusion, the optimum conditions for bioleaching of uranium from El-Sella mineralisation using A. clavatus are 9 days of incubation, 30^°C and agitation speed of 175 rpm. A. clavatus represents an excellent candidate for uranium bioleaching from its ore.

KEYWORDS:

• Bioleaching
• El-Sella
• uranium
• Aspergillus clavatus
• morphogenesis

Acknowledgments

This work was jointly supported by Zagazig University and the Nuclear Materials Authority, Cairo, Egypt. We are grateful to the reviewers, Mrs Melanie Porter of Taylor & Francis, Abingdon, and the Editor, Dr Michael Brett-Crowther, for their clarity and patience.

Disclosure statement

No potential conflict of interest was reported by the author.